Sure, everyone knows Tomboy, F-spot, Beagle, MonoDevelop, Muine, Blam! or Monodoc. But there are a lot of other interesting Mono/GTK# applications out there that need your attention. Join us for a quick listing of the not-so-well-known GTK# apps and you will witness yourself that the platform is flourishing.

"As far as I know, java cross-platform problems were ironed out years ago"

Then I invite you to go to www.gay.com and try out their chat application on Linux (assuming you have no moral objections, obviously...), with the latest JRE you can find. It's better than it used to be - you can get all the way up to the point of actually trying to enter a room, which doesn't work. Works fine on Windows, using the same Java release.